U.S. patent application number 10/344717 was filed with the patent office on 2004-02-12 for method and statistical micromixer for mixing at least two liquids.
Invention is credited to Dietrich, Thomas, Freitag, Andreas, Hessel, Volker, Lowe, Holger, Schiewe, Jorg.
Application Number | 20040027915 10/344717 |
Document ID | / |
Family ID | 7653784 |
Filed Date | 2004-02-12 |
United States Patent
Application |
20040027915 |
Kind Code |
A1 |
Lowe, Holger ; et
al. |
February 12, 2004 |
Method and statistical micromixer for mixing at least two
liquids
Abstract
The invention relates to a procedure and a micromixer for mixing
at least two fluids. The aim of the invention is to reduce the
mixing time of the micromixer compared to micromixers known to the
art while maintaining high mixing quality and small structural
dimensions. The inventive procedure is characterized by the
following steps: a plurality of separated fluid currents of both
fluids are brought together and alternately adjacent fluid lamellae
of both fluids are formed: the combined fluid currents are carried
away and a focused total fluid current is formed; the focused total
fluid current is fed as fluid jet into an expansion chamber; and
the resulting mixture is drawn off. The micromixer comprises a
plurality of alternately adjacent fluid channels (2, 3) which open
into an inlet chamber (4). A focusing channel (5) is in fluid
connection with said inlet chamber and opens into an expansion
chamber (6). The inventive procedure and micromixer are especially
advantageous in that they are suitable for the production of
emulsions and dispersions.
Inventors: |
Lowe, Holger; (Oppenheim,
DE) ; Schiewe, Jorg; (Mainz-Hechtsheim, DE) ;
Hessel, Volker; (Hunstetten-Wallbach, DE) ; Dietrich,
Thomas; (Frankfurt am Main, DE) ; Freitag,
Andreas; (Frankfurt am Main, DE) |
Correspondence
Address: |
Hudak & Shunk Company
Suite 307
2020 Front Street
Cuyahoga Falls
OH
44221
US
|
Family ID: |
7653784 |
Appl. No.: |
10/344717 |
Filed: |
July 28, 2003 |
PCT Filed: |
August 23, 2001 |
PCT NO: |
PCT/EP01/09728 |
Current U.S.
Class: |
366/341 |
Current CPC
Class: |
B01J 2219/00783
20130101; B01F 25/23 20220101; B01F 25/4338 20220101; B01J 19/0093
20130101; B01F 25/433 20220101; B01F 33/3012 20220101; B01J
2219/0086 20130101; B01J 2219/00835 20130101; Y10S 366/03 20130101;
B01F 33/3011 20220101; B01J 2219/00831 20130101; B81B 1/00
20130101; B01F 35/514 20220101; B01F 25/312 20220101; B01F 33/3039
20220101; B01F 33/3045 20220101; B01F 25/25 20220101; B01J
2219/00826 20130101; B01J 2219/00889 20130101 |
Class at
Publication: |
366/341 |
International
Class: |
B81B 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 2000 |
DE |
10041823.6 |
Claims
1. Procedure for mixing at least two fluids comprising the
following steps: a multitude of separate fluid currents of the two
fluids, each of a width in the range of 1 .mu.m to 1 mm and a depth
in the range of 10 .mu.m to 10 mm, are brought together and
alternately adjacent fluid lamellae of the two fluids are
generated; the combined fluid currents are carried away and a
focused total fluid current is generated; the focused total fluid
current is fed as fluid jet into an expansion chamber with a larger
cross section than the focused total fluid current perpendicular to
the flow direction of the focused total fluid current; the
resulting mixture is drawn off.
2. Procedure according to claim 1, characterized by the fact that
the combined fluid currents are focused in such a way that the
ratio between the cross section of the focused total fluid current
and the sum of the cross sections of the fluid currents to be
combined, all perpendicular to the flow direction, is in the range
of 1:1 to 1:500, preferably in the range of 1:2 to 1:50.
3. Procedure according to one of claims 1 or 2, characterized by
the fact that the ratio of the length of the focused total fluid
current and its width is in the range of 1:1 to 30:1, preferably in
the range of 1.5:1 to 10:1.
4. Procedure according to one of the previous claims, characterized
by the fact that the focused total fluid current enters the
expansion chamber as fluid jet in such a way that stationary
vortices are generated on both sides of the fluid jet on at least
one plane.
5. Procedure according to one of the previous claims, characterized
by the fact that after having been fed into the expansion chamber,
at least part of the fluid current is drawn off while again being
focused.
6. Procedure according to one of the previous claims, characterized
by the fact that the following two steps are executed once or in
several repetitions: after previously being fed into the expansion
chamber, at least part of the fluid current is carried away and
forms a focused fluid current; the focused fluid current is fed
into an additional expansion chamber having a larger cross section
than the focused fluid current perpendicular to the flow direction
of the focused fluid current; wherein the resulting mixture is
drawn off after the last step.
7. Procedure according to one of the previous claims, characterized
by the fact that an additional fluid, as for example a fluid
containing an additive for stabilizing the mixture, is fed into the
expansion chamber.
8. Procedure according to one of the previous claims, characterized
by the fact that at least part of the resulting mixture is drawn
off the area or areas of the expansion chamber with vortices being
generated.
9. Procedure according to one of the previous claims, characterized
by the fact that the first two steps are each executed twice or
several times, simultaneously and spatially separately, and that
the resulting two or more focused total fluid currents are fed into
the common expansion chamber.
10. Static micromixer (1) for mixing at least two fluids, with a
multitude of alternately adjacent fluid channels (2, 3) of a width
in the range of 1 .mu.m to 1 mm and a depth in the range of 10
.mu.m to 10 mm for separately supplying the fluids as fluid
currents; an inlet chamber (4) into which the fluid channels enter;
a focusing channel (5) fluidly connected to the inlet chamber (4)
for carrying away the fluid currents combined in the inlet chamber
(4) and generating a focused total fluid current; an expansion
chamber (6), into which the focusing channel (5) enters and into
which the focused total fluid current runs as fluid jet, with a
larger cross section than the focusing channel (4) perpendicular to
the axis of the focusing channel (4), and at least one outlet
channel (7) fluidly connected to the expansion chamber (6) for
drawing off the resulting mixture.
11. Static micromixer according to claim 10, characterized by the
fact that in its interior the inlet chamber (4) has a concave or
semi-concave shape on at least one plane, wherein the concave
surface (8) into the center of which the focusing channel (5) runs
is located opposite the surface into which the fluid channels
enter.
12. Static micromixer according to claim 10 or 11, characterized by
the fact that the ratio between the cross section of the focusing
channel (5) and the sum of the cross sections of the fluid channels
(2, 3) entering into the inlet chamber (4), always perpendicular to
the channel axis, is in the range of 1:1.5 to 1:500, preferably in
the range of 1:2 to 1:50.
13. Static micromixer according to one of claims 10 through 12,
characterized by the fact that the ratio between the length of the
focusing channel (5) and its width is in the range of 1:1 to 30:1,
preferably in the range of 1.5:1 to 10:1.
14. Static micromixer according to one of claims 10 through 13,
characterized by the fact that the ratio between the cross section
of the expansion chamber (6) and the cross section of the focusing
channel (5) entering into the expansion chamber, in at least a
central area, perpendicular to the channel axis is in the range of
1.5:1 to 500:1, preferably in the range of 2:1 to 50:1.
15. Static micromixer according to one of claims 10 through 14,
characterized by the fact that the expansion chamber (6) opens into
an additional focusing channel (5') serving as outlet channel (7)
for drawing off and re-focusing at least part of the total fluid
current.
16. Static micromixer according to one of claims 10 through 15,
characterized by a sequence of one or several additional focusing
channels (5', 5") into which open the respective upstream expansion
chambers (6, 6', 6") for drawing off and focusing at least part of
the total fluid current, and one or several additional expansion
chambers (6', 6") into which the respective upstream additional
focusing channels (5', 5") enter, and with at least one outlet
channel (7) fluidly connected to the last expansion chamber (6") in
the sequence for drawing off the resulting mixture.
17. Static micromixer according to one of claims 10 through 16,
characterized by the fact that one or several supply channels (9a,
9b) enter into the expansion chamber (6) for supplying an
additional fluid, such as for example a fluid containing an
additive for stabilizing the mixture.
18. Static micromixer according to one of claims 10 through 17,
characterized by one or several additional outlet channels (10a,
10b) connected to the expansion chamber (6) for drawing off the
resulting mixture.
19. Static micromixer according to one of claims 10 through 18,
characterized by a deflector structure (11) disposed in the
expansion chamber (6) for the purpose of deflecting the fluid
jet.
20. Static micromixer according to one of claims 10 through 19,
characterized by the fact that the multitude of adjacent fluid
channels (2, 3; 12, 13), the inlet chamber (4; 14) into which the
fluid channels (2, 3; 12, 13) enter, and the focusing channel (5;
15) fluidly connected to the inlet chamber (4; 14) each are
provided two or several times and that the two or more focusing
channels (5; 15) enter into a common expansion chamber (16).
21. Static micromixer according to one of claims 10 through 20,
characterized by the fact that the structures of the fluid channels
(2, 3), of the inlet chamber (4), of the focusing channel (5), and
of the expansion chamber (6) are constructed as recesses and/or
penetrations in a plate serving as mixing plate (20) and
manufactured of a material sufficiently inert for the fluids to be
mixed, and that these open structures are closed in by a cover
and/or base plate (21, 22) fluidly connected to the mixing plate,
wherein the cover and/or base plate (21, 22) are equipped with
supply devices (23, 24) for the two fluids and/or at least one
outlet (25) for the resulting mixture.
22. Static micromixer according to claim 21, characterized by a
distribution plate (26) located between the mixing plate (20) and
the base plate (22), fluidly tightly connected to the same and
serving the purpose of separately supplying the fluids from the
supply devices in the base plate (22) to the fluid channels (2, 3)
in the mixing plate (20).
23. Static micromixer according to one of claims 21 or 22,
characterized by the fact that at least the mixing plate (20) and
the cover and/or base plate (23, 24) are manufactured from a
transparent material, in particular, glass or quartz glass.
Description
DESCRIPTION
[0001] The invention relates to a procedure and a static micromixer
for mixing at least two fluids.
[0002] When mixing at least two fluids, the goal is to achieve an
even distribution of the two fluids within a particular time
period, in general the briefest possible period. For this purpose,
mixing processes with a high specific application of energy are
desirable. Advantageous are mixing processes with directed
currents, which make the actual mixing processes foreseeable by
using models. It is particularly advantageous for this purpose to
use static micromixers like the ones described in the overview by
W. Ehrfeld, V. Hessel, H. Lowe in Microreactors, New Technology for
Modern Chemistry, Wiley-VCH 2000, pages 41 to 85. With static
micromixers known to the art, mixing times of between 1 s and few
milliseconds are obtained by generating alternately adjacent fluid
lamellae with a thickness in the .mu.m range. In contrast to
dynamic mixers wherein turbulent flow conditions are prevailing,
the given geometry allows an exact adjustment of the width of the
fluid lamellae and thus of the diffusion paths. The very narrow
distribution of the mixing times achieved hereby gives room to
multiple possibilities of optimizing chemical reactions with regard
to selectivity and yield. An additional advantage of the static
micromixer is the miniaturization and thereby the capability of
integration into other systems, such as heat exchangers and
reactors. Potential applications are fluid/fluid and gas/gas
mixtures, including reactions in the corresponding regimes, as well
as fluid/fluid emulsions, gas/fluid dispersions, solid/fluid
dispersions, and thus also multiphase and phase transfer reactions,
extractions, and absorption.
[0003] A static micromixer based on the principle of
multi-lamination has on one plane a micro-structured interdigital
structure of intermeshing channels with a width of 25 .mu.m or 40
.mu.m (ibid, pages 64 to 73). The channels divide the two fluids to
be mixed into a multitude of separate fluid currents configured to
flow parallel to one another in opposite directions and alternating
with one another. The adjacent fluid currents are carried
vertically from the plane upward through a slot and brought into
contact with one another. The possibility of reducing the channel
geometry and thus the fluid lamellae width down to the lower pm
range by structuring procedures suitable for mass production is
limited.
[0004] An additional reduction of the fluid lamellae generated by
the multi-lamination principle can be achieved by so-called
hydrodynamic focusing. A static micromixer of this type for
converting hazardous materials is presented by T. M. Floyd et al.
on pages 171 to 179 in Microreaction Technology: Industrial
Prospects; Proceedings of the Third International Conference on
Microreaction Technology/IMRET3, editor: W. Ehrfeld, Springer 2000.
Alternately adjacent channels for the two fluids to be mixed run in
a semicircle and enter radially from the outside into a chamber
stretched into funnel shape which then opens into a narrow, long
channel. The fluid lamellae current combined in the chamber is
thereby transferred into the narrow channel, which causes the fluid
lamellae width to be reduced. With reduced lamellae widths in the
lower pm range, as well, diffusion-related mixing times in
millisecond range are obtained, which is still too long for some
applications, in particular, for ultra-fast reactions. Furthermore,
due to the long channel functioning as reaction space, this
micromixer has large dimensions.
[0005] The invention relates to the object of creating a procedure
and a static micromixer for mixing at least two fluids in order to
make quick mixing of the fluids possible while obtaining high
mixing quality and providing a device with small dimensions.
[0006] The object is achieved according to the invention by a
procedure according to claim 1 and a static micromixer according to
claim 10.
[0007] Hereinafter, the term of fluid will be understood as a
gaseous or liquid substance or a mixture of substances of this kind
which may contain one or several solid, liquid, or gaseous
substances in dissolved or dispersed state.
[0008] The term of mixing comprises also the processes of
dissolving (blending), dispersing, emulsifying, and suspending. As
a consequence, the term of mixture comprises solutions, fluid/fluid
emulsions, gas/fluid, and solid/fluid dispersions.
[0009] The term of a multitude of fluid currents or fluid channels
is understood as two or more, preferably three or more,
particularly preferably five or more, fluid currents or fluid
channels. For two fluids A, B, alternately adjacent fluid lamellae
or fluid channels mean that these run alternately adjacent,
generating a sequence of ABAB, on at least one plane. For three
fluids, A, B, C, the term of "alternately adjacent" comprises
differing sequences, as for example, ABCABC or ABACABAC. The fluid
lamellae or fluid channels can also run alternately adjacent on
more than one plane, as for example, in two dimensions offset
chessboard-like in relation to one another. The fluid currents and
fluid channels corresponding to the different fluids are preferably
running in the same or in opposite directions, parallel to one
another.
[0010] The procedure according to the invention for mixing at least
two fluids comprises at least four steps: in the first step, a
multitude of separate fluid currents of the two fluids, each of a
width in the range of 1 .mu.m to 1 mm and of a depth in the range
of 10 .mu.m to 10 mm, are brought together and alternately adjacent
fluid lamellae of the two fluids are generated. In the second step,
the fluid currents combined in this way are carried away and formed
into a focused total fluid current. In the third step, the
resulting total fluid current, as fluid jet, is fed into an
expansion chamber having a larger cross section in comparison to
the focused total fluid current perpendicular to the flowing
direction of the focused total fluid current. In the final step,
the resulting mixture is drawn off.
[0011] The currents are brought together in such a way that the
fluid currents, which at first are separate, flow into one space.
In this process, the fluid currents may run parallel, or run into
one another, for example, radially inward. When the currents are
brought together, fluid lamellae are generated the cross sections
of which at first correspond to those of the fluid currents. By
carrying off the fluid currents as focused total fluid current, the
width and/or cross section of the fluid lamellae are reduced, while
at the same time, the flow velocity is increased. The resulting
accelerated focused total fluid current is fed into the expansion
chamber as fluid jet. The broadening of the fluid lamellae in the
expansion chamber causes forces (shearing forces) to arise
perpendicular to the main flow direction which permit shorter
mixing times to be obtained in comparison to solely diffusive
mixing. In particular, the process of fragmentation into individual
particles as discontinuous phase within a continuous phase and
thereby the generation of emulsions and dispersions is
advantageously influenced. A particular advantage in this context
is the effect of the fluid jet as suction and carrier jet as well
as the occurrence of directed vortices.
[0012] Preferably, the combined fluid currents are focused in such
a way that the ratio between the cross section of the focused total
fluid current and the sum of the cross sections of the fluid
currents to be combined, always perpendicular to the flow
direction, is in the range of 1 to 1.5 through 1 to 500, preferably
in the range of 1 to 2 through 1 to 50. The smaller the ratio, the
more the lamellae width is reduced and the more the flow velocity
is increased at which the focused total fluid current is fed into
the expansion chamber as fluid jet. Advantageously, the cross
section of the focused total fluid current remains constant over
its length. It is also conceivable to provide a cross section which
decreases in direction of the expansion chamber, while the above
ratio remains in effect for the range with the smallest cross
section.
[0013] Preferably, the ratio between the length of the focused
total fluid current and its width is in the range of 1 to 1 through
30 to 1, preferably in the range of 1.5 to 1 through 10 to 1. In
this context, the focused total fluid current is to be, as far as
possible, sufficiently long to enforce a sufficient focusing effect
while retaining the laminar flow conditions. However, in the
interest of brief mixing times, the focused total fluid current
should be designed to be short in order to permit the fluid jet to
be fed into the expansion chamber as fast as possible.
[0014] Advantageously, the focused total fluid current is fed into
the expansion chamber as fluid jet in such a way that vortices, in
particular, stationary vortices are generated at least on one
plane, preferably on both sides of the fluid jet. Stationary
vortices of this type are generated, in particular, in the areas
along which the fluid jet passes, thereby causing these areas to
rotate. Preferably, the fluid jet is fed into the space
symmetrically so that stationary vortices are generated at least on
one plane on both sides. If the expansion chamber is broadened not
only with regard to width, but also over the entire cross section
in comparison to the focused total fluid current, it is
particularly advantageous to have stationary vortices generated on
all sides around the fluid jet. The shearing forces arising in the
stationary vortices with at least partially turbulent flow
conditions have a positive effect on the mixing process.
Advantageously, the expansion chamber is constructed in such a way
that the vortices are not generated in so-called still water zones,
but in flow-through areas.
[0015] According to one embodiment, after the fluid current has
been fed into the expansion chamber, at least one part of the fluid
current is again drawn off and focused. This may involve the entire
fluid jet leaving the expansion chamber, or only a part thereof,
while the other part is advantageously drawn off as finished
mixture. One advantage obtained by the re-focusing process is the
fact that additional areas which have not yet been completely mixed
are brought into contact. In this case, the focused fluid current
is advantageously again fed into an additional expansion chamber as
fluid jet and vortices are generated.
[0016] According to a further embodiment, the following steps are
repeated once or several times. In the first of the said steps, at
least part of the fluid current, after previously having been fed
into the expansion chamber, is formed into a focused fluid current
and carried away. In the second step, the focused fluid current is
fed into a further expansion chamber which has a larger cross
section than the focused fluid current perpendicular to the flow
direction of the focused fluid current. After these steps have been
executed once or several times, the resulting mixture is drawn off.
Due to the repeated processes of focusing and feeding into an
expansion chamber, a particularly intensive mixing action is
achieved, which is advantageous, in particular, for the generation
of emulsions and dispersions with small particle sizes. For the
advantageous execution of the focusing and feeding processes,
please refer to the preferred embodiments listed.
[0017] Advantageously, an additional fluid is fed into the
expansion chamber. This additional fluid may be fed in at one or
several points which preferably are disposed symmetrically to the
fluid jet. The additional fluid may contain an additive for
stabilizing the mixture, as for example, an emulsifier.
[0018] Advantageously, at least one part of the resulting mixture
is drawn out of the area or areas of the expansion chamber while
vortices are being generated. In this context, the resulting
mixture may be drawn off in one or several currents which
preferably are arranged symmetrically to the fluid jet. In this
context, it is particularly advantageous to draw the fluid from the
areas of the stationary vortices in which the mixture is of high
mixing quality.
[0019] According to a preferred embodiment, the focused total fluid
current is directed to a structure which is located in the
expansion chamber and deflects the fluid jet. This deflector
structure may be a flat or a bowed surface or a structure for
deflecting and/or splitting the fluid jet. Equally, the wall of the
expansion chamber opposite the point at which the focusing channel
enters may be constructed in such a way that it serves as deflector
structure. With this embodiment, a pre-laminated and focused total
fluid current is used and extremely high specific energy densities
and thus a high degree of turbulence are obtained. This strong
turbulence leads to the generation of small vortices, which in turn
leads to very small particle diameters, for example, droplet
diameters in emulsions, due to the arising strong shearing forces.
In contrast to procedures known to the art, a generation of
preliminary emulsions is not required.
[0020] According to a further embodiment, the first two steps are
executed twice or several times simultaneously and spatially
separately. This accordingly causes two or several focused total
fluid currents to be obtained which are then fed into a common
expansion chamber. In this context, it is particularly advantageous
to feed the focused total fluid currents as fluid jet into the
common expansion chamber in such a way that they meet, i.e. that
they collide. The total fluid currents to be fed in can contain the
same fluids or differing fluids which are not mixed until they
reach the common space and make contact. Here, as described before,
additional steps, such as renewed focusing and feeding as fluid jet
into an expansion chamber, may follow. As with the preceding
embodiment using a deflector structure, extremely high specific
energy densities and thus a high degree of turbulence are obtained
when using two or several pre-laminated and focused total fluid
currents; which causes the generation of very small particle
diameters, particularly with suspensions, dispersions, and
emulsions.
[0021] The static micromixer according to the invention for mixing
at least two fluids comprises a multitude of alternately adjacent
fluid channels, an inlet chamber, a focusing channel, an expansion
chamber, and an outlet channel for drawing off the resulting
mixture. The multitude of alternately adjacent fluid channels has a
width in the range of 1 .mu.m to 1 mm and a depth in the range of
10 .mu.m to 10 mm for the separate supply of the fluids as fluid
currents. The inlet chamber into which the fluid channels enter
serves to combine the multitude of separate fluid currents of the
two fluids. The focusing channel is fluidly connected to the inlet
chamber in order to carry away the fluid currents combined in the
inlet chamber and form a focused total fluid current. The expansion
chamber into which the focusing channel runs and into which the
focused fluid current enters as fluid jet has a larger cross
section than the focusing channel perpendicular to the axis of the
focusing channel. The at least one outlet channel fluidly connected
to the expansion chamber serves the purpose of drawing off the
resulting mixture.
[0022] Preferably, the inlet chamber has in its interior a concave
or semi-concave shape on at least one plane, while the concave
surface to the center of which the focusing channel runs is
disposed opposite the surface into which the fluid channels run.
Due to the concave shape, it is possible to quickly bring the
currents together and carry them off into the focusing channel
while fluid lamellae are being generated. However, it is also
conceivable to carry the combined fluid currents gradually in the
direction of the focusing channel, for which process the inlet
chamber is constructed in a way to stretch into a V-shape or funnel
shape on at least one plane.
[0023] In the interest of simple technical implementation, it is
advantageous to design the fluid channels, the inlet chamber, the
focusing channel and/or the expansion chamber with the same depth.
In this context, it is also advantageous to arrange the points
where the fluid channels enter on one plane, at least in the area
of the inlet chamber.
[0024] Preferably, the focusing channel is constructed in such a
way that the ratio between the cross section of the focusing
channel and the sum of the cross sections of the fluid channels
entering into the inlet chamber, always perpendicular to the
respective channel axis, is in the range of 1 to 1.5 through 1 to
500, preferably, in the range of 1 to 2 through 1 to 50. Thereby,
an additional reduction of the lamellae width and/or the cross
section in comparison to the given width of the fluid channels is
achieved, and combined with this, an increase in the flow velocity.
Advantageously, the cross section of the focusing channel remains
essentially constant over its entire length. It is also conceivable
that the cross section of the focusing channel decreases in
direction of the expansion chamber and that the above ratio of the
cross sections is applicable for the area with the smallest cross
section.
[0025] Preferably, the ratio between the length of the focusing
channel and its width is in the range of 1 to 1 through 30 to 1,
preferably in the range of 1.5 to 1 through 10 to 1. In this
context, the length of the focusing channel is advantageously
selected in such a way that focusing on high flow velocity while
generating the fluid lamellae is achieved and that in the interest
of fast mixing, the fluid current is fed quickly into the expansion
chamber.
[0026] According to one embodiment, the expansion chamber is
constructed as a channel with a wider cross section than the
focusing channel and follows the latter in longitudinal
direction.
[0027] Preferably, the ratio between the cross section of the
expansion chamber and the cross section of the focusing channel
entering into the expansion chamber, perpendicular to the channel
axis, is in at least a central area in the range of 1.5 to 1
through 500 to 1, preferably in the range of 2 to 1 through 50 to
1. Due to the broadening in the transitional area between the
focusing channel and the expansion chamber, the focused total fluid
current is fed into the expansion chamber as fluid jet, during
which process forces arise perpendicular to the fluid jet which
promote fast mixing. These cross-acting forces promote the process
of the fragmentation of the fluid lamellae into individual
particles, particularly during the formation of emulsions and
dispersions. Depending on the design of the expansion chamber,
vortices which change in time or are stationary are generated
laterally to the fluid jet while it is being injected. It is
advantageous for the expansion chamber to have its interior shaped,
on at least one plane, in a way suitable for the generation of
stationary vortices. This makes it possible to avoid still water
zones so that the fluid constantly flows through all areas of the
expansion chamber.
[0028] According to one embodiment, the expansion chamber opens
into an additional focusing channel serving as outlet channel. This
channel serves the purpose of drawing off and refocusing at least
part of the total fluid current. Advantageously, the additional
focusing channel follows the first focusing channel entering into
the expansion chamber in longitudinal direction, in order to catch
at least part of the fluid jet entering into the expansion
chamber.
[0029] A further embodiment of the static micromixer is equipped
with a series of one or several additional focusing channels into
which opens the respective previous expansion chamber, as well as a
series of one or several expansion chambers. The additional
focusing channels serve the purpose of drawing off and focusing at
least part of the total fluid current and enter into the respective
subsequent additional expansion chamber. An outlet channel fluidly
connected with the last expansion chamber in the series serves to
draw off the resulting mixture. Static micromixers of this type
with focusing channels and expansion chambers arranged in series
are particularly advantageously suited for the production of
emulsions and dispersions with tight particle size distribution.
Advantageously, the cross section of the additional focusing
channel is smaller than or equal to the cross section of the
preceding focusing channel.
[0030] According to a further embodiment, one or several supply
channels enter into the expansion chamber or the additional
expansion chambers in order to supply an additional fluid. Fluids
of this type can contain an additive for stabilizing the mixture,
as for example, an emulsifier. The supply channels are
advantageously disposed symmetrically in relation to a plane on
which the axis of the focusing channel lies.
[0031] According to a further embodiment, the expansion chamber has
one or several outlet channels connected thereto in order to draw
off the resulting mixture. The outlet channels are preferably
located in the areas in which stationary vortices are generated.
Here as well, the outlet channels are advantageously disposed
symmetrically in relation to a plane on which the axis of the
focusing channel lies.
[0032] Advantageously, the expansion chamber is configured with a
structure in such a way that the fluid jet is directed to this
structure and deflected. This deflector structure may have a flat
or bowed surface or a structure for deflecting and/or splitting the
fluid jet. Advantageously, the deflector structure is formed by a
wall opposite the point at which the focusing channel enters into
the expansion chamber, or is an integrated part of the same.
[0033] According to the embodiment according to claim 20, the
multitude of adjacent fluid channels, the inlet chamber into which
the fluid channels enter, and the focusing channel fluidly
connected to the inlet chamber each are provided twice or several
times, and the two or several focusing channels enter into the one
common expansion chamber. In this context, the focusing channels
are advantageously arranged in such a way that they enter into the
common expansion chamber so that the fluid jets collide in the
expansion chamber, which further considerably heightens the mixing
effect. The two or several multitudes of adjacent fluid channels,
inlet chambers, and focusing channels are disposed spatially
separately and only fluidly connected via the common expansion
chamber. These structures may serve to supply the same fluids, as
for example twice the fluids A, B, or differing fluids, as for
example the fluids A, B, and C, D.
[0034] According to a preferred embodiment, the structures of the
fluid channels, the inlet chamber, the focusing channel, and the
expansion chamber are constructed as recesses and/or penetrations
in a plate serving as mixing plate and manufactured of a material
of sufficient inertness for the fluids to be mixed. These open
structures are closed in by a cover and/or base plate fluidly
tightly connected to the mixer plate, wherein the cover and/or base
plate are equipped with supplying devices for the two fluids and/or
at least one outlet for the resulting mixture. Recesses, such as
grooves or pocket holes, are enveloped by material on a plane as
well as perpendicular to the same. Penetrations, such as slots or
holes, on the other hand, pierce the material, i.e. they are
enveloped by the material only laterally on one plane. The recesses
and penetrations are closed in by the cover or base plate, while
fluid-conducting structures, such as channels and chambers, are
formed. The supplying devices and/or outlets in the cover or base
plate may be implemented in the form of grooves and/or bores.
[0035] Depending on the fluids used, different materials, such as
polymer materials, metals, alloys, glass, in particular,
photo-structurable glass, quartz glass, ceramic materials, or
semiconductor materials, such as silicon, may be considered as
suitable materials. Plates with a thickness of 10 .mu.m to 5 mm are
preferred, while thicknesses of 50 .mu.m to 1 mm are particularly
preferred. Suitable procedures for fluidly connecting the plates
tightly with one another are, for example, compression, use of
seals, bonding, thermal or anodic bonding and/or diffusion
welding.
[0036] If the static micromixer is equipped with additional
focusing channels and expansion chambers, these are preferably
disposed on the one mixer plate. However, it is also conceivable to
construct these on one or several additional mixing plates fluidly
connected to the first mixing plate and, if warranted, to
additional mixing plates.
[0037] According to one variant of this preferred embodiment, the
static micromixer is equipped with a distribution plate inserted
between the mixer plate and the base plate, fluidly tightly
connected to these two plates, and serving to separately supply the
fluids from the supplying devices in the base plate to the fluid
channels of the mixing plate. For this purpose, the distribution
plate advantageously is equipped with a row of holes for each fluid
to be supplied, with each hole exactly assigned to one fluid
channel. In this way, for two fluids, the first row serves to
supply the first fluid, while the second row serves to supply the
second fluid.
[0038] Preferably, at least the mixing plate and the cover and/or
base plate are manufactured of a transparent material, in
particular, of glass or quartz glass. Particularly preferred is the
use of photo-structurable glass which, when using a
photo-lithographic procedure, permits precise microstructuring. If
the static micromixer is also equipped with a distribution plate,
this preferably is as well manufactured of transparent material of
this type. A particular advantage in this context is the fact that
the mixing process occurring in the static micromixer can be
observed from the outside.
[0039] Known precision-mechanical and micro-technical production
procedures may be considered as procedures for structuring the
plates, such as laser ablation, spark-eroding, injection molding,
stamping, or electro-deposition. Also suitable are LIGA procedures
which include at least the steps of structuring with energy-rich
radiation and electro-deposition as well as, if warranted, by
molding.
[0040] The procedure according to the invention and the static
micromixer are advantageously used for executing chemical reactions
with two or more educts. For this purpose or for the above named
applications, means for controlling the chemical reaction are
advantageously integrated into the static micromixer, such as for
example temperature or pressure sensors, flow meters, heating
elements, or heat exchangers. In a static micromixer according to
claim 20, these means may be disposed on the same mixing plate or
plates or on the additional plates which are arranged above and/or
below and functionally connected to the same. In order to execute
heterogeneously catalyzed chemical reactions, the static micromixer
may also be equipped with catalytic material.
[0041] Below, embodiments of the static micromixer according to the
invention are explained with reference to drawings.
[0042] They show:
[0043] FIG. 1a a static micromixer comprising a cover plate, mixing
plate, distribution plate, and base plate, each separated from the
others, in perspective view;
[0044] FIG. 1b the mixing plate according to FIG. 1a, in a top
view;
[0045] FIG. 2 a mixing plate with an outlet channel constructed as
focusing channel, in a top view;
[0046] FIG. 3 a mixing plate with several focusing channels and
expansion chambers disposed in series, in a top view;
[0047] FIG. 4 a mixing plate with a mixing chamber with supply and
outlet channels, in a top view;
[0048] FIG. 5 a mixing plate with a deflector structure disposed in
the expansion chamber, in a top view;
[0049] FIG. 6 a mixing plate with a deflector structure formed by
the wall of the mixing chamber, in a top view;
[0050] FIG. 7 a mixing plate according to FIG. 6, but with outlet
channels disposed laterally, in a top view;
[0051] FIG. 8 a mixing plate according to FIG. 7 with additional
supply channels, in a top view;
[0052] FIG. 9 a mixing plate with two focusing channels disposed
opposite of one another and entering into a common expansion
chamber, in a top view;
[0053] FIG. 10a a light-microscopy image of a static micromixer
according to FIG. 1 a during the mixing process of a dyed and a
colorless liquid at a volumetric flow rate of each 100 ml/h;
[0054] FIG. 10b an image as in FIG. 10a, but at 300 ml/h;
[0055] FIG. 10c an image as in FIG. 10a, but at 500 ml h.
[0056] FIG. 1a shows in perspective view a static micromixer 1 with
a cover plate 21, a mixing plate 20, a distribution plate 26, and a
base plate 22, each separate from the others.
[0057] The cover plate 21, the mixing plate 20, and the
distribution plate 26 each are equipped with a supply line 23 for
the fluid A and a supply line 24 for the fluid B in the shape of a
bore. The bores are configured in such a way that when the plates
are stacked one over the other, the supply lines 23, 24 are in
fluid connection with the supply structures 23, 24 of the base
plate 22. The supply line 23 for fluid A and the supply line 24 for
fluid B are disposed on the base plate 22 in the form of grooves in
such a way that fluid A can be supplied to the distribution
structure 27, and fluid B to the distribution structure 28 of the
distribution plate 26, located above, without substantial pressure
loss. The distribution plate 26 is equipped with a distribution
structure 27 for fluid A and a distribution structure 28 for fluid
B, each in the form of a row of holes piercing the plate.
[0058] The mixing plate 20 shown in FIG. 1b in detail in a top view
is equipped with fluid channels 2, 3, an inlet chamber 4, a
focusing channel 5, and an expansion chamber 6. The outlet 25 in
the form of a bore in the cover plate 21 is disposed in such a way
that when the plates are stacked one over the other, the outlet 25
is fluidly connected to the expansion chamber 6 of the mixing plate
20. The channels 2 for fluid A have a shorter length than the
channels 3 for fluid B. The sides of channels 2, 3 facing away from
the inlet chamber 4 are running parallel to one another; while
channels 2 for fluid A are running alternately adjacent to the
channels 3 for fluid B. In a transitional area, the distance of the
channels from one another diminishes in direction of the inlet
chamber 4. In the area where the currents enter into the inlet
chamber 4, the channels 2, 3 are again running parallel. In order
to achieve an even volumetric flow rate over all channels 2, 3 for
each individual fluid, the channels 2, 3 are constructed in equal
length. This has the effect that those ends of the fluid channels
2, 3 which are distant from the inlet chamber 4 each form an arc.
The bores of the distribution structures 27, 28 of the distribution
plate 26 also each form an arc in such a way that the ends of the
channels 2, 3 each make fluid contact with a bore. The inlet
chamber 4 into which the fluid channels 2, 3 enter is constructed
in semi-concave shape on the plane of the fluid channels. In the
central area of the concave surface 8 located opposite the points
at which the fluid channels 2, 3 enter, the inlet chamber 4 opens
into the focusing channel 5. The focusing channel 5 enters into the
expansion chamber 6 formed by a channel which in comparison to the
focusing channel 5 is wider and extends in the same longitudinal
direction. The structures of the fluid channels 2, 3, of the inlet
chamber 4, of the focusing channel 5, and of the expansion chamber
6 are designed as penetrations piercing the material of the mixing
plate 20. These structures, which are open on two sides, are
covered by the distribution plate 26 located underneath and the
cover plate 21 located above and form channels and/or chambers.
[0059] In the operational micromixer 1, the plates 21, 20, 26, and
22 which here are shown as separate are stacked on top of one
another and fluidly connected tightly to one another, whereby the
open structures, such as grooves 23, 24 and penetrations 2, 3, 4,
5, and 6, are covered while channels and chambers are being formed.
The resulting stack made up of the plates 21, 20, 26, and 22 may be
lodged in a mixing housing equipped with suitable fluid connections
for the supply of two fluids and the removal of the fluid mixture.
Furthermore, a compression force may be applied through the housing
onto the stack of plates in order to provide a fluidly tight
connection. It is also conceivable to operate the stack of plates
as micromixer 1 without housing, for which purpose fluid
connections, such as for example hose nozzles, are advantageously
connected to the supply devices 23, 24 and the outlet 25 of the
cover plate 21.
[0060] During the actual mixing process, a fluid A and a fluid B
are fed into the supply bore 23 and into the supply bore 24,
respectively, of the cover plate 21. These fluids flow through the
supply structures 23 and 24, respectively, of the plates 20, 26,
and 22 and from there are evenly distributed into the respective
distribution structures 27 and 28 constructed as bores. From the
bores of the distribution structure 27, fluid A flows into the
channels 2 of the mixing plate 20 located exactly above the said
distribution structure 27. Equally, fluid B flows from the bores of
the distribution structure 28 into the channels 3 located exactly
above the distribution structure 28. The fluid currents A, B
flowing separately into the fluid channels 2, 3 are brought
together in the inlet chamber 4 and form alternately adjacent fluid
lamellae of the sequence ABAB. Due to the semi-concave shape of the
inlet chamber 4, the combined fluid currents are quickly
transferred into the focusing channel 5. The resulting focused
total fluid current is fed into the expansion chamber 6 as fluid
jet. The resulting mixture of the fluids A, B is drawn off through
the outlet bore 25 of the cover plate 21 located above in the end
area of the expansion chamber 6.
[0061] FIG. 2 shows a mixing plate 20 in a top view, wherein the
supplying fluid channels 2, 3 for the fluids A and B are
represented in simpler form than in FIG. 1b. The inlet chamber 4 is
constructed in semi-concave shape, wherein the concave surface 8 is
located opposite the areas in which the channels 2, 3 enter. In the
central area of the concave surface 8, the inlet chamber 4 opens
into the focusing channel 5. The focusing channel 5 is of equal
width over its entire length and enters into the expansion chamber
6. On the side opposite the focusing channel 5, the expansion
chamber 6 opens into an additional focusing channel 5' serving as
outlet channel 7. In the top view, the expansion chamber 6 has an
essentially circular shape which broadens toward the additional
focusing channel 5'. Due to this construction, the interior of the
expansion chamber 6 has on the plane shown a shape suitable for the
generation of stationary vortices. Thereby, still water zones are
avoided so that the fluid constantly flows through all areas of the
expansion chamber 6.
[0062] The fluid currents of fluids A and B leaving channels 2, 3
are brought together in the inlet chamber 4 and, due to the
semi-concave shape, are quickly transferred into the focusing
channel 5 as combined fluid lamellae current. The substantially
narrower cross section of the focusing channel 5 in comparison to
the inlet chamber 4 causes the fluid current to be focused, i.e. it
causes a reduction of the fluid lamellae width combined with a
simultaneous increase of the flow velocity. The total fluid current
focused in this way enters into the expansion chamber 6 as fluid
jet 3 and there is laterally broadened, with the possibility of
vortices being generated on both sides of the fluid jet. The mixed
product obtained in the expansion chamber 6 is drawn off by the
additional focusing channel 5' while again being focused. The
obtained fluid mixture is drawn off at the end of the additional
focusing channel 5' and upward into a cover plate located above the
mixing plate 20.
[0063] The mixing plate 20 shown in FIG. 3 in a top view is
equipped with a sequence of several expansion chambers 6, 6', 6"
and focusing channels 5, 5', 5" all of which are arranged in
series. The design and shape of the supplying fluid channels 2, 3,
of the inlet chamber 4, of the focusing channel 5, and of the
expansion chamber 6 are equal to those of the corresponding
structures of the mixing plate shown previously in FIG. 2. Opposite
the focusing channel 5, the expansion chamber 6 opens into an
additional focusing channel 5' which runs in the same longitudinal
direction as the focusing channel 5. This additional focusing
channel 5' on its part enters into an additional swirl chamber 6'
which in turn opens into an additional focusing channel 5'". This
is followed by a third expansion chamber 6'" which then finally
opens into the additional focusing channel 5'" serving as outlet
channel 7. The focusing channels 5, 5', 5", 5'" are of essentially
the same length and are arranged longitudinally in the same
direction, with expansion chambers 6, 6', 6'" disposed between
them. The direction of the fluid jet is indicated by arrows in the
expansion chambers 6, 6', 6'". Here, stationary vortices indicated
by spiral-shaped lines are generated on both sides of the fluid
jet. The focusing channel disposed behind an expansion chamber thus
catches at least part of the fluid jet entering into the expansion
chamber as well as part of the obtained mixed product. Thanks to
the fact that the current is repeatedly focused and fed into an
additional expansion chamber, mixtures, in particular emulsions and
dispersions, of high quality can be obtained with brief mixing
times.
[0064] In FIG. 4, the mixing plate 20 of an additional static
micromixer according to the invention is shown in a top view. The
design and configuration of the channels 2, 3, of the inlet chamber
4, of the focusing channel 5, of the expansion chamber 6, and of
the additional focusing channel 5' serving as outlet 7 correspond
to those of the structures represented in FIG. 2. Two supply
channels 9a, 9b enter into the expansion chamber 6 on the side on
which the focusing channel 5 enters and are arranged symmetrically
to the same. These supply channels 9a, 9b can be used to feed an
additional fluid, as for example an emulsifier, into the area of
the generated vortices in the expansion chamber 6. Furthermore, two
additional outlet channels 10a, 10b are connected to the expansion
chamber 6, are located on the side where the expansion chamber 6
opens into the additional focusing channel 5', and are arranged
symmetrically to the additional focusing channel 5'. These
additional outlet channels 10a, 10b can be used to draw part of the
resulting mixture out of the expansion chamber 6. For this purpose,
the supply channels 9a, 9b and the additional outlet channels 10a,
10b are fluidly connected to corresponding supply or outlet
structures in the cover plate above and/or the base plate. The
configuration of the supply channels 9a, 9b and the additional
outlet channels 10a, 10b here is only shown in exemplary fashion.
In this way, corresponding supply and/or outlet channels may also
be located in the area of the base plate and/or cover plate below
and above the expansion chamber 6, respectively. Depending on the
application, it may be advantageous if only one or several supply
channels or only one or several outlet channels enter into the
expansion chamber 6.
[0065] FIG. 5 shows in a top view a mixing plate 20 of a further
static micromixer according to the invention with structures as
shown in FIG. 2, wherein the expansion chamber 6, in addition,
contains a deflector structure 11. The deflector structure 11 is
formed by a cuboid structure where one surface of the cuboid is
located opposite to and at a distance from the point at which the
focusing channel 5 enters. This has the effect that the focused
total fluid current entering into the expansion chamber 6 hits the
deflector structure 11 and is deflected from there into the
expansion chamber 6 while vortices are generated on both sides. In
this way, a particularly intensive mixing process is achieved with
very brief mixing times. The resulting mixture is drawn off through
the additional focusing channel 5' serving as outlet channel 7.
[0066] A mixing plate 20 of a further embodiment of the static
micromixer according to the invention is shown in FIG. 6 in a top
view. The configuration of the fluid channels 2, 3, of the inlet
chamber 4, and of the focusing channel 5 corresponds to that
represented in FIG. 2. The focusing channel 5 opens into an
expansion chamber 6 which has no outlet channel on the plane shown.
On the plane shown, the expansion chamber 6 has an essentially
round shape, wherein the surface opposite the focusing channel 5 is
curved inward into the expansion chamber. This has the effect that
the fluid jet moving from the focusing channel 5 into the expansion
chamber 6 hits the curved part of the surface serving as deflector
structure 11 and is deflected on both sides into the expansion
chamber 6. The resulting mixture is drawn off through an outlet
channel 7 located in the cover plate not shown here and indicated
by a circular dotted line.
[0067] FIG. 7 shows a variant of the embodiment of the mixing plate
20 of the static micromixer represented in FIG. 6. Here as well, a
deflector structure 11 is formed by an area of the wall of the
expansion chamber 6 which is curved inward into the expansion
chamber 6. Two outlet channels 10a, 10b enter the expansion chamber
6. These outlet channels are disposed essentially opposite the
deflector structure 11 and symmetrically to the axis of the
focusing channel 5. In comparison to FIG. 6, the obtained mixture
is therefore not drawn off upward out of the expansion chamber, but
rather laterally from the areas of vortex generation.
[0068] FIG. 8 represents a variant of the embodiment shown in FIG.
7. In addition to the additional outlet channels 10a, 10b, two
supply channels 9a, 9b enter the expansion chamber 6. The supply
channels are disposed on both sides of the deflector structure 11
and adjoining the same as well as symmetrically to the axis formed
by the focusing channel 5. As also described with reference to FIG.
4, these supply channels can serve to supply a fluid supporting the
mixture, in particular, the emulsion or dispersion, such as for
example to supply an emulsifier. The additional outlet channels
10a, 10b and the supply channels 9a, 9b are fluidly connected to
corresponding supply and outlet structures, respectively, in the
base and/or the cover plate.
[0069] A mixing plate 20 of a further embodiment of the static
micromixer is shown in FIG. 9 in a top view. From two opposite
sides, two focusing channels 5, 15 enter into a common expansion
chamber 16. The focusing channels 5, 15 are connected to an inlet
chamber 4, 14, respectively, into which enter the fluid channels 2,
3; 12, 13. The two focusing channels 5, 15 are running
longitudinally in the same direction. One outlet channel 10a, 10b
enters on either side into the expansion chamber 16 on the same
plane as and perpendicular to the focusing channels 5, 15. The
fluid currents leaving the fluid channels 2, 3; 12, 13 are combined
in the inlet chamber 4 as well as in the inlet chamber 14, then
quickly fed into the focusing channel 5, 15 and focused. The fluid
lamellae currents thus combined and focused leave the focusing
channels 5, 15 as fluid jets, enter the common expansion chamber 16
from opposite sides, and collide while generating vortices, which
causes an intensive mixture to be achieved within extremely short
time. The obtained mixed product is drawn out of the common
expansion chamber 16 on either side through the outlet channels
10a, 10b which are fluidly connected to corresponding structures in
the base and/or cover plate.
[0070] Embodiment
[0071] Micro-structured glass plates were used to execute the
static micromixer represented in FIGS. 1a and 1b. The mixing plate
20 and the distribution plate 26 each had a thickness of 150 .mu.m
while the closing base plate 22 and cover plate 21 each had a
thickness of 1 mm. Bores with a diameter of 1.6 mm were chosen for
supply to structures 23, 24 in the cover plate 21, the mixing plate
20, and the distribution plate 26. The distribution plate 26 was
equipped with two rows of each 15 long holes of a length of 0.6 mm
and a width of 0.2 mm as distribution structures 27, 28. The fluid
channels 2, 3 of the mixing plate 20 had a width of 60 .mu.m and a
length of 11.3 mm or a length of 7.3 mm, respectively.
[0072] In the area where the channels 2, 3 enter into the inlet
chamber 4, the segments located between the channels 2, 3 had a
width of 50 .mu.m. The inlet chamber 4 had a width of 4.3 mm in the
area where the fluid channels 2, 3 enter and at the opposite side,
the width of the focusing channel of 0.5 mm. Since all structures
of the mixing plate 20 were constructed as penetrations, the fluid
channels 2, 3, the inlet chamber 4, the focusing channel 5, and the
expansion chamber 6 all have a depth equal to the thickness of the
mixing plate of 150 .mu.m. The length of the inlet chamber 4, i.e.
the distance between the points where the fluid channels 2, 3 enter
and the point where the focusing channel 5 enters, was only 2.5 mm,
in order to permit the combined fluid currents to be drawn off and
focused quickly. The ratio between the cross section of the
focusing channel and the sum of the cross sections of the fluid
channels 2, 3 therefore was 1 to 3.6. With the focusing channel 5
having a length of 2.5 mm, a ratio between length and width of 5 to
1 was obtained. The focusing channel 5 opened in longitudinal
direction into the expansion chamber 6 constructed similar to a
channel with a length of 24.6 mm and a width of 2.8 mm. The opening
angle of the side walls of the expansion chambers 6 in the
transitional area between the expansion chamber 6 and the focusing
channel 5 amounted to 126.7.degree.. The four plates shown in FIG.
1a had outer dimensions of 26.times.76 mm. The plates were
structured by photo-lithography using photo-structurable glass in a
known process as described by Th. R. Dietrich, W. Ehrfeld, M.
Lacher, and B. Speit in Microstrukturprodukte aus
fotostrukturierbarem Glas [Microstructured Products made of
Photo-Structurable Glass], F&M 104 (1996), pages 520 to 524.
The plates were fluidly tightly connected by thermal bonding.
[0073] The fact that all components of the static micromixer were
manufactured of glass made it possible to observe the mixing
process under a light-optical microscope, as shown by the
respective images of the FIGS. 10a, 10b, and 10c under illumination
from below.
[0074] For this purpose, the process of generating emulsions using
silicon oil with water containing a blue dye was investigated.
FIGS. 10a through 10c show only the section of the areas where the
fluid channels 2, 3 enter into the inlet chamber 4, the focusing
channel 5, and the expansion chamber 6.
[0075] The fluid channels carrying the water treated with the blue
dye can be clearly recognized by their darker gray shade in the
left area where the fluid channels enter the inlet chamber. Since
the supplied silicon oil as well as the segments manufactured of
glass which are located between the fluid channels 2, 3 are
transparent, they cannot be differentiated here.
[0076] In all three images, the processes of bringing the separate
fluid currents together and of drawing off the combined fluid
currents while focusing them can be clearly detected. The fluid
lamellae structure remains intact during these processes.
[0077] In FIG. 10a which was taken for each silicon oil and water
with a volumetric flow rate of 100 ml/h, fast broadening of the
total fluid current at the time of entry into the expansion chamber
can be detected.
[0078] In FIG. 10b which was taken with volumetric flow rates of
each 300 ml/h, the formation of a fluid jet at the time of entry
into the expansion chamber can be clearly detected, while the fluid
jet later fans out. Vortices are generated on both sides of the
fluid jet in the expansion chamber.
[0079] The clearest view of the generation of stationary vortices
on both sides of the fluid jet entering into the expansion chamber
6 is gained from FIG. 10c which was taken with volumetric flow
rates of each 500 ml/h.
1 List of Drawing References 1 static micromixer 2 fluid channel
for fluid a 3 fluid channel for fluid b 4 inlet chamber 5 focusing
channel 5', 5", . . . additional focusing channel 6 expansion
chamber 6', 6", . . . additional expansion chamber 7 outlet channel
8 concave surface 9a, 9b supply channel 10a, 10b additional outlet
channels 11 deflector structure 12 fluid channel for fluid a 13
fluid channel for fluid b 14 inlet chamber 15 focusing channel 16
common expansion chamber 20 mixing plate 21 cover plate 22 base
plate 23 supply device for fluid a 24 supply device for fluid b 25
outlet 26 distribution plate 27 distribution structure for fluid a
28 distribution structure for fluid b
* * * * *